Carbon fiber has been used in various portions of stringed instruments since the 1970s. Carbon fiber laminates are generally stiff and light; however they do not generally have the acoustic characteristics desired by those who are used to the sound of wood. The natural acoustic characteristics of carbon laminates tend to sound metallic and lack the warmth of wood. In addition, solid carbon fiber laminates generally have a higher density as compared to wood, and for a given weight, have significantly lower bending stiffness. Therefore, designing carbon fiber laminates with an acoustic response, tone, and feel of wood instruments is challenging.
Many different variations of wood and carbon fiber bracing have been attempted to provide an acceptable level of performance with respect to vibration, structural integrity, acoustic response, tone, and feel of the stringed instrument. In addition, many different types of soundboards have been attempted which have been formed of solid carbon, or by bonding carbon sheets together or to a foam core or a wood core. These types of soundboards in many instances have resulted in a soundboard which is over damped, and in instances where the face sheets of carbon laminate of the soundboard are too thin, then the soundboard is prone to damage upon exposure to minor impacts.
Bracing for guitars have also incorporated the use of foam or syntactic foam cores. Syntactic foam cores are generally formed by a process where layers of a mesh are filled with microballoons which are disposed or laid into a laminate. The mesh is filled with resin during the soundboard fabrication process creating an internal core. This type of bracing tends to be too highly damped and/or heavy, especially with respect to syntactic foam cores.
A typical acoustic guitar has a hollow body or sound box connected to a neck. The hollow body has a soundboard with a sound hole, a back or bottom board spaced from the soundboard, and a shaped side wall which connects between the soundboard and backboard. These components in the past have been typically constructed of choice pieces of wood in order to produce instruments of superior quality.
An acoustic guitar has a series of strings strung at substantial tension from a bridge on the soundboard, across the soundboard proximate to a sound hole, and along the neck. The string tension creates forces which act on the soundboard and which, over time, may cause bending, cracking or other damage to the soundboard. The damage can result in structural failure and altered intonation of the acoustic guitar. As such, the guitar, notably the sound box, must be constructed in a relatively strong and stable manner, without making it to heavy, or limiting its response.
In high quality acoustic guitars, the soundboard must be capable of vibration to provide superior acoustic performance while being rigid so that it withstands the forces created by the tensioned strings. These requirements are at cross-purposes, and have been very difficult to achieve, particularly when the soundboard is constructed from a material other than choice wooden materials. The soundboard is in close union with the remaining pieces of the sound box.
Acoustic guitars are constructed so as to amplify the sound wave produced by the vibration of the strings, via a resonance body having a soundboard. The sound wave created by the vibrating strings is introduced into the resonance body through the bridge provided on the soundboard. Inside the resonance body, the sound wave is resounded and amplified within the resonance body. If the resonance body is not constructed correctly, the sound may be emitted in a muffled or dampened manner.
Prior art designs have also attempted to utilize a number of different types of materials for braces or to form the soundboard or other portions of the sound box. Examples of these prior art devices may be found in U.S. Pat. Nos. 6,943,283; 4,353,862; 7,612,271; 5,396,823; 4,429,608; 4,836,076; 5,333,527; 6,333,454; 7,208,665; 5,406,874; 5,952,592; 4,969,381; 6,664,452; 7,268,280; and 7,790,970 the entire contents all of which being incorporated herein by reference in their entireties.
The present invention provides for a uniformly strong soundboard which in conjunction with the sound box delivers clean, brilliant sound. The construction of the soundboard provides for easier and more economical manufacture when state of the art equipment is used.
All U.S. patents and applications all other published documents mentioned anywhere in this application are incorporated herein by reference in their entireties.
Without limiting the scope of the invention in any way, the invention is briefly summarized in some of its aspects below.
The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention.